.410 might be possible

Saiga .410s aren't $149 any more, and you'd have to find one, pay the FFL fees at both ends, plus shipping, and then you'd still have to buy all the parts and do all the work to convert it to AK configuration.

Building a parts kit into a pistol is legal. Same should apply to building a kit into a shotgun.

Kits are back down to $119 right at the moment.

Doing some preliminary doodling, it looks like it should be possible to build a standard-length AK in .410, bypassing the whole "buy and Saiga and convert it" thing.

A .410 conversion should be roughly similar to a .308 conversion. A .410 shell will fit in a .308 magazine. Do the usual mods to fit a .308 mag.

Unlike a regular cartridge, a shotshell is longer after it's fired. This should not be a problem.

The Saiga 12 and 20 gauge rifles use a two-piece bolt head, but the .410 is one-piece. I figured the two-piece bolts were for ease of manufacture or to make extraction easier, but Saiga figured the .410 didn't need it.

The .410 rim diameter is .524", a 54R is .567", so there's room to open up a standard AK bolt to .410 size.

Numrich has 3" chambered .410 barrels for $50-ish. As a wild guess, I'd expect they'd be thinner than AK barrels and would require bushings at the tenon and to mount the RSB, GB, and FSB.

Lore has it that Saiga went to the new gas block with the oversize floating piston to get sufficient zip to cycle the action with low-pressure shotgun shells. Given the AK's flexibility in handling lower pressure metallic cartridges, I'd give the stock configuration a try before getting fancy. Then I'd open up the gas port a bit, space the gas piston to put it deeper into the gas block, and maybe ream out the gas block as far as practical and sleeve the piston. If none of those worked, a homemade gas block with a Saiga-sized piston ought to work. The floating tappet shouldn't be necessary.

If you started with a Yugo gas block, you could make it adjustable by modifying the gas shutoff.

Looking at pictures (I've never had the opportunity to handle a Saiga in the metal) it looks like the front trunnion is designed with some kind of guide ribs to help the shotshell go into the breech straight. The bolt also has fingers going forward, supposedly for that purpose. A shotshell's flat front means it has little room for deviation from the barrel centerline, whereas a pointy rifle bullet just has to hit the hole somewhere.

Again, I'd try it and see how things worked before over-planning things. Put a mark on the top of a shell with a felt tip, use that as a clock to see where the end of the shell hits the breech face. I can think of half a dozen ways to add guides or fillers to direct the cartridge if needed.

A 410 saiga is little differant. The barrel is shrouded on the top over the bullet guide to feed the round. I have one Ill post some picks later.

Im planning on doing a 410 barrel possable for my switch barrel build. also now planing a smokeless powder muzzel loader barrel for it as well.

brass shotgun shells can be had and can be made rimless and would allow a standard bolt to be used if opend up to 308 win sizes. 444 marlin brass can be converted into
410,and even 30-06 brass can be converted into rimless 410. I sugessted a 410 SGFH type round with a protruding .45 rifle bullet here a about a year ago.

I tried a 3" shell in a G3 mag. Fits fine. The M-14 mag, not so well - the lips don't go all the way to the back of the mag, and snag the rim, which then jams solid. The lips need to be extended to the back, or trimmed forward at an angle.

the bolt is long in the head like a 308 with a weird ejector hole more like a AK 74.
' the barrel has protrusions/shroud/bullett guide/feed ramp out past the breach aproximently 3/4" above the it and about 3/8" below it and slightly to the right hand side.

the bottom of the carrer is shaped differantly were it slides over round as well. the bolt is small stem btw.
the gun is laid out like a 308 with the longer bolt and breach moved ahead.

The factory mag is a single stack and is designed to kick the round up at a very high angle into the protruding shroud and then it is guided back down into the lower guide and into the chamber. My mag is a 3" Id like to have some of the 2.5" but there harder to find.

here is some pics.

If I was going to do it id build it like a standard AK and move the mag well back Id use a single stack mag possably a G3 with spacers in it Id replicate the barrel shrouds as well. Id also consider a 2.5" shell in a custom mag as well to allow more trigger guard area. there are more brass cases out there in 2.5 as well and they can be made from 444 marlin as its about 2.5" long. std ammo is cheaper as well in 2.5 also .

I have considerd the barrel shroud on my 444 Marlin build as well.

these 410 guns have been converted to 444 marlin in the past but they would not feed well with a stock mag. there was also a nice 500 S&W built on a 410 sagia.

Honestly there still reasonably priced and can be found used. so if I wasent trying to da swith barrel build and thought it was cool to have a SG barrel as well Id just by one .

I paid $175 for mine used at a gun shop not to long ago. the Factory trigger with the teater toter transfer bar is much much better than my 308 sagia and i have never understood why they didnt use the same setup in the 308.

Yea its dirty I havent shot it much at its kind of just a toy cant hunt deer in my state with 410 unfortunatly or Is build a 3.5" rifled barrel and use SGFH type shells in the SG zones and a little small for phesants ect and I have better shotguns for that any way.

Hmm. If I'm figuring it right, the Saiga mag tilts the shell sharply up at the front, where it touches the top barrel extension? Then it just rides the extension right into the breech?

I think it goes up and then comes back down i a straight position and is guided by the lower guide,

Hmm, looks like the ordinary AKM trunnion rivet pattern instead of the inline pattern of the Saiga-12.

pretty close the LH side has a extra rivet that works as a mag stabelizer. there is also some differances in the trunion were the extra long extractor rotaates against the trunion. the extractor rotates all the was from the upper shroud to the side of the trunion

That U-shaped(?) shell guide(?) looks like it's held in place with a small rivet on the right side.

NOPE
It as well as the upper shroud are part of the barrrel. the breach is recessed so to copy this barrel you will have to bore in about 3/4" mill out the areas around the shrouds and then chamber the barrel in deep. this is also going to require a 22mm (i think its 22 mm) od on your barrel blank. it might be possable to make a sleave to do this on a low pressure 410 round. and still use the thiner 410 blanks. I looked at doing a rifled barrel for a 410 slug a while back and there is more than meets the eye here.